Electric switch



Sept. 10, 1929. F2. BIGENWALD ELECTRIC SWITCH Filed Oct. 4, 1928Inventor RudoLF ELgenvx/QLC(3 )o5 MW/MM/ Hts ttor'neg.

Patented Sept. 10, 1929.

UNITED sTATEs PATENT OFFICE.-

RDOLF FIBIGENWAII'.|D,`OF HIRSCHGARTEN; GERMANY, ASSIGNOR TO GENERALELEC- l TRIC COMPANY, A CORPORATION '0F NEW YORK.

SWITCH.

Application filed October f1, 1928, Serial No. 310,320, and in GermanyNovember 17, 1927.

. My invention relates to electric switchesof the liquid break type andparticularly to eX- plosionchamber casings for such switches. Explosionchamber casings commonly have been constructed of metal with aninsulation lining and wit-h an insulating bushing in the- It has beenproposed to construct *L bottom. the explosion chamber casing in part ofa strong insulating material, such for example i0 as hard paper, butdiliiculties havel been. en-

countered in securing together the parts forming the complete casing, Itis an object of 4my invention to provide an improved eX- plosion chambercasing, constructed in part at least of insulating material havingsimple and effective means for securing together the various partsthereof.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

Referring td thedrawing the single ligure of which represents vafragmentary cross sec-A tional View of'a liquid break switch involvingmy invention, the enclosing vesselor tank l contains insulating liquid 2in which the contacts are immersed. Supported by the insulator'bushing 3and connected with the contact stud .tis the plate 5 forming the top-ofthe explosion chamber casingfin which is mounted the fixed contact 6.This contact is of the well known socket-type which is adapted toreceive the movable contact rod 7. In the complete switch `two similarcontact rods 7 are secured at 'opposite ends of the bridge 8, the tworods being associated with two similar explosion chamber casings in thecommon and well understood manner.

The cylindrical wall 10 and the bottom v v wall l1, of each explosionchamber casing are of insulating material` such as hard paper. Tofacilitate firmly securing these two'walls together and the cylindricalwall to the top plate 5, I construct the cylindrical wall with conicalupper and lower portions, the upperY portion flaring outwardly and thelower portion Haring inwardly. It will be understood that if the hardpaper is impregnated with tacts in the explosion chamber, I have shownbakelite, the cylindrical wall will be deformed to produce the conicalportions before the` bakelite is cured. The upper plate 5 is providedwith thev internal flange 12 having a conical outer face and screwthreaded to this plate 1s the clamping ring 13 having a coni- 55 calinner face. By tightening this ring the wall 10 is vlirmly clamped tothe top plate 5. The bottom plate 11 has a conical peripherycorresponding with the lower conical portion of the cylindrical wall,thus lirmlv securing the bottom wall against being blown out by internalpressure. rIlhe throat bushing 15 is also of insulation and may be ofhard paper like the walls. 10 and 11. I have shown the bottom wall 11with the material thereof arched inwardly thereby better to withstandthe great pressure to which it is sometimes subjected. As a protectionagainst the eects of an arc drawn between the conthe separate insulatingcylinder 1G which member may be constructed of a material which whilenot necessarily having the f strength of the wall 10 may be betteradapted to withstand the eiects of the are and hot gases, and thusprotect the wall 10. The separately formed members 10, 1l and 15 arepreferably impregnated with bakelite or a similar material and afterbeing assembled are cured, thus securely binding together the severalparts.

l/Vhile I have described only one embodimentof my invention, I do notwish to be limited to the particular form shown and described as it willbe apparent that many modiications therein may be made without departingfrom the scope of my invention as set forth in the appended claims.y

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An explosion chamber casing for a liquid `break switch comprising acup-like insulating member having ,an outwardly inclined edge portion, acover engaging the inner face of saidinclined edge portion, andapclamping member cooperating with the cover and engaging the outerfacegof said inclined edge portio'n.

` 2. An explosion chamber casing for a liquid break switch comprising acup-like insulating i member having a conical edge portion, a coverhaving a conical portion engaging the inner face of said 'edge portion,and a clamping member adjustably secured to the cover and having aconical portion engaging the outer v face of said edge portion.

3. An explosion chamber casing for a liquid break switch comprising ahollow cylindrical insulating member having an inwardly inclined endportion, and an insulating end...y plate therefor ittingywithin andretained by said inclined end portion. i 4. An explosion chamber casingfor a liquid break switch comprising a hollow cylindrical insulatingmember having an inwardly inclined conical endportion, and an insulatingend plate therefor'y having a central contact opening and a conicalperiphery fitting Within said conical end portion, said end plate havingan insulating` bushing arranged in the opening therein.

5. An explosion chamber casing for a liquid break switch comprising acylindrical mem bcr of hard paper having its upper and lower endspressed to form respectively outwardly flaring and inwardly flaringconical portions, a metal cover therefor having a flange engaging theinner face of the outwardly flaring conical portion, a ring threaded tosaid cover and enaging the outer face of the outwardly flaring conicalportion, an end plate of hard paper fitting within and retained by saidinwardly flaring conical portion, and an insulating bushing secured insaid end plate.

vIn witness whereof, I have hereunto set my hand this 18th day ofSeptember, 1928.

f RUDOLF BIGENWALD.

